Why is rotational speed important?
Faster RPM speeds result in less latency. Keep in mind that this latency is not the same as RAM latency. Latency for hard drives is a much simpler concept. Ok, so your platter is spinning around. When the head (read or write) is in the proper location at the cylinder, the correct sector might not be there. Since the platter is spinning, the head sits and waits for the correct sector to come whizzing along, and then it is able to do its read/write operation. The reason why increasing spindle speed helps performance is because it reduces the time that the head is sitting there waiting for the sector to show up. Nowadays, the standard, vanilla hard drive is 5,400 RPM, with higher performance ones being 7,200 RPM, and even higher performance ones (mostly for servers) being 10,000 RPM. However, keep in mind that this latency is reduced WHEN THE HARD DRIVE IS ALREADY SPINNING. If your hard drive is “resting”, then it must spin up to speed first. In this scenario, both a 5,400 RPM drive and a
